Adjustable orthopedic connections

ABSTRACT

The disclosure includes methods and systems for making orthopedic connections where there is unique adjustability to the connection. Illustratively, one embodiment provides a connecting assembly for connecting a plurality of orthopedic components. Such connecting assemblies can include a first orthopedic component that provides a female bore. Additionally the assembly can include a second orthopedic component that can be or include a male-type connecting member that is positionable in the bore of the first orthopedic component. In one preferred form, the male-type connecting member will be a quasi-spherical member. The quasi-spherical member can include a textured outer surface, e.g., for contacting one or more walls or surfaces in the bore in a fashion that removeably locks or helps to removeably lock or fix the quasi-spherical member in the bore.

CLAIM OF PRIORITY

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/910,700, filed on Dec. 2, 2013, the benefit ofpriority of which is claimed hereby, and which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to medical technology and incertain aspects to methods and systems for adjustably connectingorthopedic components, e.g., an articulating member to a stem or base.

BACKGROUND

As further background, the head or other portions of a proximal humeruscan be replaced with prosthetic devices, e.g., to treat advanceddegeneration of the proximal humerus. Due to the variability of theanatomy, e.g., head height, diameter, inclination and offset to thehumeral canal, effective anatomical reconstruction can often necessitatea modular system offering a variety of implant configurations.

OVERVIEW

The present disclosure provides, in certain aspects, unique methods andsystems for integrating or connecting orthopedic components.Illustratively, one aspect of the present disclosure provides aconnecting assembly for connecting a plurality of orthopedic components.This particular connecting assembly includes a first orthopediccomponent that provides a bore. The assembly also includes a secondorthopedic component that can be or include a quasi-spherical memberthat is positionable in the bore of the first orthopedic component forremoveably locking the quasi-spherical member to the first orthopediccomponent. The quasi-spherical member includes a textured outer surfacesuch as any of those disclosed herein. The textured outer surface cancontact walls of the bore in a manner that removeably locks or helps toremoveably lock the quasi-spherical member to the first orthopediccomponent. While not necessary, any suitable combination of thefollowing features can be incorporated into or associated with theconnecting assembly. The quasi-spherical member can be part of a bonescrew or fastener. Such a bone screw can include a shaft (e.g., a fullyor partially threaded shaft with or without one or more tapered and/orone or more non-tapered longitudinal sections) that extends away fromthe quasi-spherical member, for example, where the quasi-sphericalmember forms all or part of a head of the screw. The orthopediccomponent can be an implant. The orthopedic component can be a boneplate. With a bone plate, the bore can extend partially or entirelythrough a wall of the plate. In some forms, a bore will extend entirelythrough a wall of the plate and a leading tip of the screw will bepassed through the bore in advance of the quasi-spherical member. Thefirst orthopedic component can be an articulating ball or head membersuch as a humeral head. The quasi-spherical member can be a modularcomponent that is connectable to a separate humeral stem component. Thetextured outer surface can cover a significant portion of thequasi-spherical member such as more than 25% or more than 50%. Thetextured outer surface can include a plurality of planar surfaceelements, e.g., with polygonal perimeters.

In one aspect, the present disclosure provides a ball-side prosthesisfor articulating with a socket in a ball and socket joint in a patient.This particular prosthesis comprises an articulating ball member thatincludes a top side and a bottom side. The top side provides a convexarticulating surface for articulating with surfaces in the socket. Thebottom side includes an opening into a bore that extends into thearticulating ball member from the bottom side toward the top side. Theprosthesis further comprises a fixation member that is anchorable to abone of the patient remaining on the ball side of the ball and socketjoint. The prosthesis further comprises a quasi-spherical member that isdisposed at a proximal end of the fixation member. The quasi-sphericalmember is positionable in the bore of the articulating ball member forremoveably locking the quasi-spherical member to the articulating ballmember. The quasi-spherical member includes a textured outer surfacesuch as any of those disclosed herein for contacting walls of the bore.While not necessary, any suitable combination of the following featurescan be incorporated into or associated with the prosthesis. The fixationmember can include an elongate stem that is receivable in anintramedullary canal on the ball side of the ball and socket joint. Thearticulating ball member can be a humeral head. The bore can include atapered segment. The fixation member and the quasi-spherical member canbe modular components that are connectable to one another, e.g., using aMorse-type taper connection. The textured outer surface can cover anysuitable percentage of the quasi-spherical member, e.g., between about10% and 100%, or between about 40% and about 99%, or between about 50%and about 90%. The textured outer surface can include a plurality ofgenerally planar faces, e.g., including generally planar faces spacedfrom one another on the quasi-spherical member and/or includinggenerally planar faces contiguous with one another on thequasi-spherical member. The textured outer surface can include aplurality of surface elements with polygonal perimeters, e.g., includingsurface elements with planar surfaces within the polygonal perimetersand/or including surface elements with convex and/or concave surfaceswithin the polygonal perimeters. The textured outer surface can includea three-dimensional tessellation incorporating polygonal surfaces. Thequasi-spherical member can approximate a honeycomb of polyhedral cells.

In one aspect, the present disclosure provides a quasi-spherical memberthat is positionable in the bore of an orthopedic component forremoveably locking the quasi-spherical member to the orthopediccomponent. The quasi-spherical member comprises a textured outer surfacethat includes a plurality of outermost extensions that are spaced fromone another on the textured outer surface and which define a firstradius of the quasi-spherical member and a plurality of innermostdepressions that are spaced from one another on the textured outersurface and which define a second radius of the quasi-spherical member.The textured outer surface can contact walls of the bore in a mannerthat removeably locks or helps to removeably lock the quasi-sphericalmember to the orthopedic component. While not necessary, any suitablecombination of the following features can be incorporated into orassociated with the quasi-spherical member or orthopedic component. Thebore can include a tapered segment with a first diameter that is twicethe first radius and a second diameter that is twice the second radius.The plurality of innermost depressions can occur on planar and/ornon-planar (e.g., concave) surfaces on the quasi-spherical member. Theplurality of outermost extensions can be symmetrical peaks on thequasi-spherical member.

In one aspect, the present disclosure provides a humeral prosthesis forarticulating with a glenoid cavity in a patient. This particular humeralprosthesis comprises a humeral head member that includes a top side anda bottom side. The top side provides a convex articulating surface forarticulating with surfaces in the glenoid cavity, e.g., a native glenoidcavity. The bottom side includes an opening into a bore that extendsinto the humeral head member from the bottom side toward the top side.The prosthesis further includes a fixation member that is anchorable toa humerus of the patient. The prosthesis further includes aquasi-spherical member that is disposed at a proximal end of thefixation member, e.g., where the quasi-spherical member is an integralpart of the fixation member. The quasi-spherical member is positionablein the bore of the humeral head member for removeably locking thequasi-spherical member to the humeral head member. The quasi-sphericalmember includes a textured outer surface such as any of those disclosedherein for contacting walls of the bore. In one embodiment, the texturedouter surface includes a plurality of outermost extensions that arespaced from one another on the textured outer surface and which define afirst radius of the quasi-spherical member and a plurality of innermostdepressions that are spaced from one another on the textured outersurface and which define a second radius of the quasi-spherical member.While not necessary, the fixation member can include an elongate stemthat is receivable in an intramedullary canal on the ball side of theball and socket joint and/or the textured outer surface can include athree-dimensional tessellation of triangular surfaces whose verticesprovide the plurality of outermost extensions.

In some aspects, the present disclosure provides systems and methodsthat can be used in a humeral reconstruction surgery in which the heador proximal end of the humerus bone is replaced or repaired, e.g.,providing surgeons with modular humeral head systems offering rapid andaccurate adjustability. In some forms, modular humeral heads will haveeccentric centers and/or be used with stemmed or stemless humeralfixation members.

Some aspects of the present disclosure involve connections between afemale-type bore in a first orthopedic member such as an orthopedicplate (e.g., a bone plate) and a quasi-spherical member or othermale-type connector of a second orthopedic member. This second membercan be any orthopedic element or device to be connected to the plate. Incertain embodiments, this second member will be something to be driveninto or otherwise received in bone, for example, to attach the plate toa bone. This second member can be a screw, fastener, pin, spike, ornail. For example, the second member can be a screw with a taperedshaft, or having a significant longitudinal section of the shaft beingtapered with or with threading. In some embodiments, the firstorthopedic member will be a non-plate orthopedic device. In someembodiments, the first orthopedic member will be an orthopedic implant(e.g., a knee, hip, shoulder, ankle, or other joint implant). Each ofthese non-limiting examples can stand on its own, or can be combined invarious permutations or combinations with one or more of the otherexamples.

BRIEF DESCRIPTION OF THE DRAWINGS

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner. In the drawings, which are not necessarilydrawn to scale, like numerals may describe similar components indifferent views. Like numerals having different letter suffixes mayrepresent different instances of similar components. The drawingsillustrate generally, by way of example, but not by way of limitation,various embodiments discussed in the present document.

FIG. 1A shows a humeral prosthesis according to one embodiment of thepresent disclosure.

FIG. 1B shows an alternative orientation of the humeral prosthesis ofFIG. 1A.

FIG. 1C shows a radiographic image of an illustrative humeralprosthesis.

FIG. 2 shows a humeral head member according to one embodiment of thepresent disclosure.

FIG. 3A shows a side, cross-sectional view of a humeral head memberaccording to one embodiment of the present disclosure.

FIG. 3B illustrates a radius of a perfect sphere.

FIG. 3C shows a quasi-spherical member with a textured outer surfaceaccording to one embodiment of the present disclosure.

FIGS. 4A-4D show quasi-spherical members with textured outer surfaces ofdifferent densities according to additional embodiments of the presentdisclosure.

FIG. 5A shows a quasi-spherical member with a textured outer surfaceaccording to one embodiment of the present disclosure.

FIG. 5B shows a quasi-ellipsoid member with a textured outer surfaceaccording to one embodiment of the present disclosure.

FIG. 6A shows a quasi-spherical member with a textured outer surfaceaccording to one embodiment of the present disclosure.

FIG. 6B shows a quasi-spherical member with a textured outer surfaceaccording to one embodiment of the present disclosure.

FIG. 7A shows a humeral member according to one embodiment of thepresent disclosure.

FIG. 7B shows a humeral member according to another embodiment of thepresent disclosure.

FIG. 8 shows a humeral member according to one embodiment of the presentdisclosure.

FIG. 9 shows a humeral member according to another embodiment of thepresent disclosure.

FIG. 10 shows a front view of a bone screw according to one embodimentof the present disclosure.

FIG. 11 shows a front view of an orthopedic assembly according to oneembodiment of the present disclosure.

FIG. 12 shows a front view of an orthopedic assembly according toanother embodiment of the present disclosure.

FIG. 13A shows a top view of an orthopedic plate according to oneembodiment of the present disclosure.

FIG. 13B is a cross-sectional view taken along view line 13B-13B fromFIG. 13A.

FIG. 13C shows part of an orthopedic plate according to anotherembodiment of the present disclosure.

DETAILED DESCRIPTION

As disclosed above, the present disclosure provides, in certain aspects,unique methods and systems for making orthopedic connections.Illustratively, some embodiments of the present disclosure provide aconnecting assembly for connecting a plurality of orthopedic components,e.g., where the connecting assembly itself provides a unique way tospatially adjust a first component relative to a second component. Suchconnecting assemblies can include a first orthopedic component thatprovides a female bore. Additionally the assembly can include a secondorthopedic component that can be or include a male-type connectingmember that is positionable in the bore of the first orthopediccomponent. In one preferred form, the male-type connecting member willinclude a quasi-spherical member. The quasi-spherical member includes atextured outer surface, e.g., for contacting one or more walls orsurfaces in the bore in a fashion that removeably locks or helps toremoveably lock or fix the quasi-spherical member in the bore. Othersuitable male-type connecting members incorporating textured outersurfaces in accordance with the present disclosure can approximate othershapes (e.g., non-spherical shapes such as a quasi-ellipsoid shape) asdiscussed elsewhere herein. In some preferred embodiments, the geometryof the textured outer surface will allow the quasi-spherical member tobe positioned and locked in the bore in a rather large number oforientations or angular positions, for example, to account forvariability in the patient's anatomy. In some instances, such aconnecting assembly will be part of a ball-side prosthesis forarticulating with a socket in a ball and socket joint in a patient. Forexample, the first orthopedic component can be an articulating ballmember such as a humeral head member that includes a top side and abottom side. The top side can provide a convex articulating surface forarticulating with surfaces in the socket. The bottom side can include anopening into the bore, e.g., extending into the articulating ball memberfrom the bottom side toward the top side. The quasi-spherical member canbe disposed at the proximal end of a fixation member that is anchorableto a bone of the patient remaining on the ball side of the ball andsocket joint. In the context of a humeral prosthesis, for example, theorientation or angular position of the quasi-spherical member in thebore can be adjusted to account for variability in things like headheight, diameter, inclination and offset to the humeral canal. In someembodiments, the first orthopedic component is a bone plate, and thesecond orthopedic component is a bone screw such as where a leading tipof a shaft of the screw is passed through the plate through the femalebore and into bone in advance of a quasi-spherical member that formspart of the screw, e.g., forming all or part of a head of the screw.Thereafter, the quasi-spherical member can be received and locked in thebore in a rather large number of orientations or angular positions forattaching the plate to bone, for example, by advancing the screw to adesired final location in the bone. Such connections can be effective toresist back-out of the screw. In some instances, a shaft or a leadingtip of a shaft never passes through a female bore in a plate. In someembodiments, a leading tip of the shaft enters bone before the screwcontacts or is associated with the plate. In some forms, a screw isadvanced to a desired final location in the bone before thequasi-spherical member is locked in the female bore, for example, wherea plate is impacted down onto a pre-positioned screw so that thequasi-spherical member is forcefully received and locked in the femalebore.

FIGS. 1A-1B show an illustrative humeral prosthesis 10. This particularhumeral prosthesis 10 includes a humeral head member 40, aquasi-spherical member 20, and a humeral fixation member 60. The humeralhead member 40 includes a top side 41 and a bottom side 42. The humeralhead member 40 can be hemispherical or partially-spherical in shape andin this particular instance the top side 41 provides a convexarticulating surface 47 for articulating with glenoid surfaces, e.g.,natural or synthetic mating glenoid surfaces of a human or animalshoulder. The humeral head member 40 can be formed with any suitablematerial including metals, ceramics, polymers or combinations of thesematerials. The humeral fixation member 60 is anchorable to a humerus.The humeral fixation member 60 includes a stem 70 which is sized andshaped to be inserted into a canal 73 of the humerus 74 (See FIG. 1C).The stem 70 can be anchored in any suitable manner such as beingcemented, non-cemented, pinned, or screwed to the surrounding bonematerial and can be configured to promote bone ingrowth. The stem 70 canbe formed with any suitable material including metals, ceramics,polymers or combinations of these materials. FIG. 1C is a radiographicimage of a humeral prosthesis implanted after an illustrative shoulderreplacement surgery. The stem 70 of the fixation member 60 can beinstalled in the canal 73 of a humerus bone 74. The humeral head member(head) 40 can be located at the proximal end 59 of the humerus 74 andcan articulate with natural or synthetic mating glenoid surfaces 58 ofthe shoulder 75.

Referring to FIGS. 1A-1B, during a shoulder replacement in which ahumeral prosthesis 10 is required and perhaps owing to variations inanatomy, a surgeon may elect to adjust the orientation or angularposition of a humeral head 40 (shown in cross section) relative to aremaining anatomical structure or another implant component such ashumeral fixation member 60. The humeral head member 40 includes a bottomside 42 that provides a bore 43 with one or more smooth walls 44. Thebore extends into the humeral head member from the bottom side towardthe top side. The bore 43 can be tapered with the opening wider at thebottom side 42 and narrowing towards a base 48 forming a bottom of thebore 43. A suitable female bore can be tapered or non-tapered. Asuitable female-type bore can be or incorporate any suitablethree-dimensional shape, e.g., incorporating rectilinear and/orcurvilinear features. A suitable female-type bore can have afrustoconical shape. Suitable shapes of a female-type bore can be orinclude full and partial forms of wedges, tapered bodies, toroids,conoids, catenoids, cubes, parallelepipeds, prisms, and combinations ofthe same. Suitable shapes include but are not limited to full or partialcylinders, cuboids, cones, pyramids, and tetrahedrons, and combinationsof the same, and in this regard, it will be understood that male-typeconnectors incorporating textured outer surfaces in accordance withcertain aspects of the present disclosure can approximate any suitableshape as well. Thus, in addition to spheres, such male-type connectingmembers can approximate non-spherical shapes, e.g., incorporating anysuitable three-dimensional rectilinear and/or curvilinear shape.Illustratively, in some preferred forms, a male-type connectorincorporating a textured outer surface in accordance with the presentdisclosure will approximate all or part of a shape like a sphere (e.g.,a partial sphere such as a hemisphere), ellipsoid, oblate spheroid,prolate spheroid, catenoid, conoid, or paraboloid of revolution.

Continuing with FIGS. 1A-B, contact between the quasi-spherical member20 and walls 44 of the bore at one or more interfaces 22 can allow asurgeon to orient the humeral head 40 in a wide range of positions, twoof which can be seen in the different angles of the humeral head 40illustrated in FIGS. 1A and 1B. FIG. 1A shows the relationship betweenthe fixation member 60 and the humeral head 40 at a first angle 17 andFIG. 1B shows the relationship between the fixation member 60 and thehumeral head 40 at a second angle 18. The geometry of thequasi-spherical member 20 can allow these angular adjustments to be madein three dimensions. During an evaluation of the orientation or angularposition of the humeral head 40, the quasi-spherical member 20 may beonly partially inserted into the bore 43. Even then, there may besufficient grip to hold the components together to allow the surgeon tojudge the suitability of the positioning. Once the humeral head 40 isdeemed by a surgeon to be suitably oriented, the quasi-spherical member20 can then be more fully inserted into the bore 43, e.g., by impactionloading accomplished by pressure, impact force or otherwise. In someinstances, forcible contact between a male-type member such asquasi-spherical member 20 and walls of the bore will be sufficient tocrush or to otherwise deform surface features of the male-type memberand/or surfaces or walls within the female bore. The shape of the bore43 including its walls 44 and the shape and surface features of thequasi-spherical member 20 can be such that the quasi-spherical membercan be positionable in the bore of the humeral head member forremoveably locking the quasi-spherical member to the humeral headmember, e.g., providing a fixed immovable connection between thequasi-spherical member 20 and the humeral head 40.

The quasi-spherical member 20 is disposed at a proximal end of thefixation member 60. In this particular embodiment, the humeralprosthesis 10 can include a narrowing and connecting member 37 which canform a transition between the quasi-spherical member 20 and the fixationmember 60. This connecting member 37 can be sized and shaped to provideclearance for adjustment of the humeral head 40 on the quasi-sphericalmember 20. The humeral head 40 can include a cannulation 55 providing anopening extending from the base 48 of the bore 43 to the articulatingsurface 47. The cannulation 55 can be used for insertion of a pin-liketool (not pictured) to separate the humeral head 40 from thequasi-spherical member 20 after the two members have been fixedlyattached by impact loading. In another example, the cannulation 55 canbe threaded to use in conjunction with a bolt (not pictured) to separatethe humeral head member 40 from the quasi-spherical member 20. Althoughthe bore 43 is illustrated as positioned on a center axis 39 of thehumeral head 40, the placement of the bore 43 can be offset from thecenter axis 39 to provide a surgeon with additional configurations forthe humeral prosthesis 10.

FIG. 2 shows a perspective view of another example of a humeral headmember 40. The bottom side 42 can include a recessed area 49 which canprovide a humeral head member 40 with a lighter weight and/or greaterorientation adjustment.

FIG. 3A shows a cross section of a humeral head 40. The bore 43 can betapered so as to include a first radius 45 positioned near the bottomside 42 and a second radius 46 positioned near the base 48. While notnecessary, the first radius 45 and the second radius 46 can be relatedto measurements on the quasi-spherical member 20 (See FIG. 3C). FIG. 3Billustrates a perfect sphere 21 having a radius 23. FIG. 3C illustratesa quasi-spherical member 20 that includes an illustrative textured outersurface 11 covering essentially the entirety of the quasi-sphericalmember 20. In accordance with certain aspects of the present disclosure,quasi-spherical members or other male-type connectors in accordance withthe present disclosure will incorporate a textured outer surfacecovering more than 50%, or more than 65%, or more than 75%, or more than85% of the quasi-spherical member or other connector. In some instances,the textured outer surface will cover between about 25% and about 50% ofthe quasi-spherical member or other connector, or between about 35% andabout 75%, or between about 50% and about 90%, or between about 60% andabout 100%.

Continuing with FIG. 3C, this particular textured outer surface 11incorporates a three-dimensional tessellation 80. A suitabletessellation can incorporate a plurality of polygonal elements such aspolygonal elements 78. In this particular instance, the polygonalelements are triangular elements or faces 81. Textured outer surfacesaccording to additional aspects of the present disclosure canincorporate other suitable three-dimensional tessellations. In certainembodiments, quasi-spherical members or other male-type connectors inaccordance with the present disclosure will mimic or approximate aplurality of stacked polyhedra such as but not limited to stacked cubes,rhombic dodecahedrons, truncated octahedrons, hexagonal prisms, ortriangular prisms. In some forms, quasi-spherical members or othermale-type connectors in accordance with the present disclosure willmimic or approximate a honeycomb of polyhedral cells including uniformand non-uniform honeycombs.

Continuing with FIG. 3C, the textured outer surface 11 includes aplurality of outermost extensions 12 which in this illustrativeembodiment occur at vertices of the triangular faces as discussed hereinbelow. A distance from the center of the quasi-spherical member 20 to anoutermost extension 12 can be equal to the first radius 45. While notnecessary, an arc connecting at least two of the outermost extension 12can have generally the same curvature as the arc of the perfect sphere21. The textured outer surface 11 includes a plurality of innermostdepressions 13 which in this illustrative embodiment occur at thecenters of the triangular faces as discussed herein below. A distancefrom the center of the quasi-spherical member 20 to an innermostdepression 13 can be equal to the second radius 46. While not necessary,an arc connecting at least two of the innermost depressions can havegenerally the same curvature as the arc of the perfect sphere 21. Asecure grip between the textured outer surface 11 and inner walls 43 ofthe bore can occur at one or more interfaces 22. While not necessary,the relationship between the first radius 45 and the second radius 46can be as follows: where R=a radius 23 of a perfect sphere 21, the firstradius 45=R+t and the second radius 46=R−t where “t” is a variable thatcan be changed to create variable textured surfaces 11.

FIGS. 4A-D illustrate a spectrum of densities of tessellation patterns80. FIG. 4A provides a quasi-spherical member 20 with a low density 28of polygonal elements 78. FIG. 4D provides a quasi-spherical member 20with a high density 27 of polygonal elements 78. FIGS. 4B-4C illustratequasi-spherical members 20 with lower and higher intermediate densities29 of polygonal elements 78. A quasi-spherical member 20 with a higherdensity will allow a higher quality of spherical mapping. As thequasi-spherical member 20 is being adjusted in the taper 44 (see FIGS.1A-B), higher quality mapping can allow a greater spectrum of possibleorientations or angular positions of the humeral head member 40 inrelation to the quasi-spherical member 20.

FIG. 4A shows features of the polygonal surface elements 78. Anindividual polygon 86 can have an exterior face 87 that forms an outersurface on the quasi-spherical member 20. The exterior face 87 caninclude a chord 89 as an edge of the exterior face 87. Each cord 89 canbe contiguous with a chord 89 of a neighboring polygon 79. The chord 89can terminate at each end in a vertex 88. Each vertex 88 of a polygon 86can be contiguous with a vertex 88 of a neighboring polygon 79. Anynumber of these exterior surface features (e.g., edges, chords, planaror non-planar faces, vertices, etc.) and/or any of the other exteriorsurface features disclosed herein that can be incorporated into atextured outer surface of a male-type connecting members can forciblycontact walls or surfaces in a female-type bore to some degree, and insome instances, can be formed with materials that cause such surfacefeatures to be crushed or to otherwise deform upon such forciblecontact, to removeably lock or help to removeably lock the male-typeconnecting member in the bore. Just to give one illustrative example, aplurality of planar or nearly planar faces on a textured outer surfaceof a male-type connecting member (e.g., a quasi-spherical member) caneach partially contact a curved wall of a female bore (e.g., cylindricalor conical).

In accordance with certain aspects of the present disclosure,quasi-spherical members or other male-type connectors in accordance withthe present disclosure will incorporate a textured outer surface thatincludes a plurality of generally planar surfaces, for example, wherethe combined area of the generally planar surfaces cover more than 50%,or more than 65%, or more than 75%, or more than 85% of thequasi-spherical member or other male-type connecting member. In someinstances, the combined area of the generally planar surfaces will coverbetween about 25% and about 50% of the quasi-spherical member or othermale-type connecting member, or between about 35% and about 75%, orbetween about 50% and about 90%, or between about 60% and about 100%.

Referring now to FIG. 5A, shown is a quasi-spherical member 20 accordingto another embodiment of the present disclosure that could beincorporated into any suitable orthopedic system or implant. On whatwould otherwise be a perfect sphere, a textured outer surface 11 in thisinstance includes a plurality of planar, circular faces 82 which arespaced from one another on the quasi-spherical member. These types ofplanar faces can have any suitable perimeter shape, e.g., incorporatingrectilinear and/or curvilinear features. Illustratively, in additionalembodiments, a textured outer surface will include a plurality of planarsurfaces that are non-circular, e.g., polygonal. One example of this isthe tessellated surface pattern shown in FIG. 3C. Additionally, it willbe understood that when a textured outer surface in accordance with thepresent disclosure incorporates circular and/or non-circular exteriorfaces, such faces need not be planar. Illustratively, in additionalembodiments, a textured outer surface will include a plurality ofnon-planar surface elements that are spaced from one another on thequasi-spherical member or other male-type connecting member. Suchsurface elements can be convex or concave or can incorporate otherthree-dimensionally curved surfaces. For example, one or more of theplanar, circular faces 82 shown in FIG. 5A could instead be slightlyconvex or slightly concave. Additionally, it will be understood that anytwo such circular or non-circular surface elements need not be spacedfrom one another on a textured outer surface of a male-type connectingmember. Select surface elements can be contiguous with one another orotherwise contact one another on the textured outer surface. FIG. 5Bshows a quasi-ellipsoid member 85 according to one embodiment of thepresent disclosure that could be incorporated into any suitableorthopedic system or implant. A textured outer surface 11 in thisinstance includes a plurality of surface elements “X” which can be anyof those disclosed herein, e.g., planar and/or non-planar surfaceelements. For example, any one surface element “X” can be a bump, bulge,lump, knob, protuberance, dimple, depression, dent, or other type ofprojection or indentation. Such features can be arranged in regular orirregular patterns. These and other surface textures disclosed hereincan be formed in any suitable manner including by cutting away, grindingaway or otherwise removing material from an initial work piece toprovide one or more surface features or elements, or by welding,adhering or otherwise adding material to an existing piece to provideone or more surface features or elements, or by casting or otherwiseinitially forming a component (e.g., using an additive manufacturingprocess) to have one or more surface features or elements.

FIGS. 6A-B illustrate variations between the flatness of the surface ofeach exterior face 87 of each polygonal element 78. FIG. 6A shows aquasi-spherical member 20 having polygons 86 that have planar faces 93.FIG. 6B shows a quasi-spherical member 20 having polygons 86 that havearcuate faces 92. The arcuate face 92 can be formed with curves having avery slight radius or formed with curves having a more pronounced radiusas discussed elsewhere herein.

FIGS. 7A-B represent two configurations of an assembly 9 that includes afixation member 60 and a quasi-spherical member 20. In FIG. 7A theassembly 9 includes at least two separate pieces. The quasi-sphericalmember 20 can include a connecting member 37 that is unitarily formedwith the quasi-spherical member, or alternatively the connecting membercan be a separately-formed piece that is subsequently connected to thequasi-spherical member using any suitable type of connection such as ataper fit or threaded connection. For example, the quasi-sphericalmember can include a female-type bore into which a male-type element ofthe connecting member is received to make a connection. Also, thefixation member 60 can include a stem cavity 76 which can receive adistal end 61 of the connecting member 37 for making a connectionbetween the two in any suitable fashion. For example, the connectionbetween the connecting member 37 and the fixation member 60 can be inany of the forms disclosed herein including in the form of a lockingtaper connection, a screw connection, a bolt connection, or a connectionemploying additional fasteners to facilitate making the connection. Forexample, the connecting member can have threads to mate with threads inthe stem cavity 76. A configuration such as illustrated in FIG. 7A canallow the mixing and matching of various forms of quasi-sphericalmember/connecting member assemblies with various forms of connectingmembers and/or fixation members 60 so that a particular patient'smorphology can be matched completely.

FIG. 7B illustrates an example of a monoblock assembly 69 in which theconnecting member 37 is not removable from the fixation member. Theseexamples should not be construed as limiting. For example, theconnecting member 37 of FIG. 7A could be integral with the fixationmember 60 instead of integral with the quasi-spherical member 20. Insuch a case, the quasi-spherical member 20 would have a cavity toreceive a proximal end of the connecting member 37. It is also possiblethat the fixation member 60 and the quasi-spherical member 20 and anypotential intermediate member be formed as a monoblock or otherwiseformed together as a single unit.

FIG. 8 illustrates an example of a humeral member 9 that includes astemless member 62. The stemless member 62 could include what isconsidered a short stem but in any event is not inserted deep into thecanal 73 of the humerus 74 and instead is anchored to more proximalportions of a humerus 74 (see FIG. 1C). While not necessary, thestemless member 62 can be connected to a distal end of a connectingmember 37, which in turn can be connected at its opposite end to aquasi-spherical member 20.

As discussed elsewhere herein, in some preferred forms, a textured outersurface of a male-type connector will exhibit or occupy only a portionof a particular shape such as a part of a sphere, part of an ellipsoid,etc. FIG. 9 shows a humeral member 9 according to one embodiment of thepresent disclosure. Member 9 includes a fixation member 60 and amale-type connector 100. A portion of the connector is shown in phantomas indicated by dashed line 101, and in this regard, it will beunderstood that connector 100 can have spherical or partial-sphericalqualities. For example, in some forms, connector 100 will be a truncatedsphere where an illustrative segment 102 of the sphere is removed ornever exists as part of the connector. While the degree or amount oftruncation shown in FIG. 9 may be useful in certain embodiments, it ismerely illustrative of those contemplated. In this truncated version ofthe connector, segment 102 is defined along a single plane so as tocreate a proximal planar surface 103. When present, such a proximalsurface can be planar or non-planar. Also, any suitable portion orpercentage of such a truncated or other partial shape can be covered bya textured outer surface.

As also discussed elsewhere herein, quasi-spherical members or othermale-type connectors in accordance with certain aspects of the presentdisclosure can incorporate a textured outer surface covering only acertain portion or percentage (e.g., between about 50% and about 90%) ofthe quasi-spherical member or other connector. Continuing with FIG. 9,in some other forms, one or more connector segments or other connectorportions such as segment 102 will be part of the connector but will bevoid of a textured outer surface such as surface 99 or will have alesser-textured, differently-textured, etc. outer surface. For example,the illustrative segment 102, when present, can have a generally smoothouter surface. In this regard, while the amount or percentage ofcoverage by the textured outer surface 99 shown in FIG. 9 may be usefulin certain embodiments, it is merely illustrative of those contemplated.Any suitable degree or percentage of coverage by a particular texturedouter surface is contemplated, e.g., more than 50%, or more than 65%, ormore than 75%, or more than 85%, or between about 25% and about 50%, orbetween about 35% and about 75%, or between about 50% and about 90%, orbetween about 60% and about 100% of the quasi-spherical member or otherconnector.

In some embodiments, a quasi-spherical member or other male-typeconnector in accordance with the present disclosure is incorporated intoan orthopedic product that is to be driven into or otherwise received inbone, for example, as a product for attaching or securing anotherorthopedic device such as a bone plate or implant to bone. In some ofthese embodiments, the orthopedic product is a bone screw, for example,where a quasi-spherical member or other male-type connector is disposedat a location along the length of the screw such as at a locationbetween the ends of the screw or at or near the end of a screw to formall or part of a screw head. Such products can be formed with anysuitable material(s), and in some instances, will include exteriorsurface that encourage bone ongrowth or ingrowth, for example, includinga blasted surface to encourage bone ongrowth.

With reference now to FIG. 10, shown is a bone screw 120 that includes aquasi-spherical member 121 disposed at a proximal end 122 of the screwto provide a screw head 123. In this particular embodiment, a femalebore 125 with a hexagonal cross section extends into the head from aproximal surface 126 of the head. Bone screw 120 also includes a shaft128. While this sort of a quasi-spherical bone screw head can be pairedwith a bone screw shaft of any suitable size, shape or configuration, inthis particular instance, the shaft extends distally from head 122 to aleading, distal tip 130 of the screw. A central cannula 131 continues onfrom female bore 125 and traverses the entire length of the screw whichcan be useful, for example, for placing the screw over a positionedK-wire. Bone screws and fasteners in accordance with the presentdisclosure can be fully or partially cannulated or non-cannulated.Cannulated regions can have any suitable wall thickness.

Continuing with FIG. 10, shaft 128 includes a proximal section 133having a first diameter and a distal section 134 having a seconddiameter that is smaller than the first diameter. Bone screw andfastener shafts in accordance with the present disclosure can haveconstant diameters or cross sections along their lengths, or a shaftdiameter or cross section can vary along its length. For example, anysection of a shaft can be tapered or non-tapered. Thus, proximal section133 and/or distal section 134 can be fully or partially tapered alongits length. While not necessary to broader aspects of the disclosure, adual- or other multi-diameter or cross section shaft can be useful in avariety of instances, for example, where shaft sections with differentdiameters or cross sections are intended to reside in different types orareas of bone. For example, when bone screw 120 is placed in a glenoid,this sort of dual-diameter arrangement can account for the smallervolume of bone or a minimum cross section of the bone anatomy (e.g.blade of scapula) located away from the point of entry of the screw aswell as the comparatively larger volume of available bone located closerto the entry point (e.g. glenoid vault). In this regard, proximalsection 133 can be considered a glenoid vault zone, and distal section134 can be considered a glenoid blade zone of screw 120 if the screwhappens to be placed in this particular anatomy.

Continuing with FIG. 10, threading 135 (not shown for clarity reasons)which can have a consistent screw pitch extends along both the proximaland distal sections of the shaft. Bone screws and fastener shafts inaccordance with the present disclosure can be fully or partiallythreaded or non-threaded. Any suitable threading can be employed, and ascrew or fastener can have different types of threading at differentlocations along a shaft. Above are just a few non-limiting examples ofhow a quasi-spherical member or other male-type connector in accordancewith the present disclosure can be paired with a shaft of any suitablesize, shape or configuration including self-drilling or self-tappingshafts.

A quasi-spherical member or other male-type connecting member of a bonescrew or other fastening-type device in accordance with the presentdisclosure can be used with (e.g, received and locked in a bore presentin) any number of implants or other orthopedic devices disclosedelsewhere herein. These include plates (e.g., bone plates) and othernon-plate orthopedic devices. One or more bone screws or otherfastening-type devices in accordance with the present disclosure can beutilized in any one device. FIG. 11 is illustrative of one such deviceand shows, for example, how different angular positions X and Y can beachieved and maintained using connections according to aspects of thepresent disclosure. In particular, FIG. 11 depicts an orthopedicassembly 140 that includes an orthopedic device 141 (e.g., a bone plateor implant) that provides a first tapered female bore 142 and a second,identical tapered female bore 143 with walls 144. These particular boreshave a shape of a frustum of a right circular cone. Although notnecessary to broader aspects of the disclosure, the bores each extendentirely through a wall or section 145 of the device. Either bore couldhave any suitable size and shape. As disclosed elsewhere herein, asuitable female bore can be tapered or non-tapered and can otherwise beor incorporate any suitable three-dimensional shape, e.g., incorporatingrectilinear and/or curvilinear features. Continuing with FIG. 11,assembly 140 also includes a first bone screw 146 and an identicalsecond bone screw 147. Each screw includes a quasi-spherical head 148and a shaft 149 extending from the head. These heads and shafts could beany combination of heads and shafts disclosed herein. In use, theleading ends of the shafts can be passed into and through the bores. Inthe FIG. 11 illustration, this passing occurs in a downward direction,i.e., the leading ends enter the frustoconcial bores through the largertop ends of the bores and exit the smaller bottom ends. Thereafter, thescrews can be advanced (e.g., into bone) until the quasi-spherical headsare received down into the respective female bores and locked therein soas to generate the different angular positions X and Y. Based on theFIG. 11 orientation, seating can also be fully or partially accomplishedby moving the bores in an upward direction relative to the heads.Although not necessary to broader aspects of the disclosure, the wallsof the bores extend fully around the seated heads, e.g., with no breaksor openings in the walls that form the frustoconcial bore shapes.

FIG. 12 shows a front view of an orthopedic assembly according toanother embodiment of the present disclosure, and shows, for example,how different angular positions X and Y can be achieved and maintainedusing connections according to aspects of the present disclosure. Inparticular, FIG. 12 depicts an orthopedic assembly 140 that includes anorthopedic device 141 (e.g., a bone plate or implant) that provides afirst tapered female bore 142′ and a second, identical tapered femalebore 143′ with walls 144′. These particular bores have a shape of afrustum of a right circular cone. Although not necessary to broaderaspects of the disclosure, the bores each extend entirely through a wallor section 145 of the device. Either bore could have any suitable sizeand shape. As disclosed elsewhere herein, a suitable female bore can betapered or non-tapered and can otherwise be or incorporate any suitablethree-dimensional shape, e.g., incorporating rectilinear and/orcurvilinear features. Such bores could extend only partially through thewall or section, for example, as shown with the elongated bore oropening in FIG. 13C. Continuing with FIG. 12, assembly 140 also includesa first bone screw 146 and an identical second bone screw 147. Eachscrew includes a quasi-spherical head 148 and a shaft 149 extending fromthe head. These heads and shafts could be any combination of thosedisclosed herein. In use, the quasi-spherical heads can be received andlocked in the respective female bores so as to generate the differentangular positions X and Y. Based on the FIG. 12 illustration, suchconnections can be achieved by moving wall or section 145 in a downwarddirection onto the screws (e.g., by impacting the device 141) so thatthe heads enter the frustoconcial bores through the larger bottom endsof the bores and move a distance in the bores toward the smaller topends until suitably locked in place. Based on the FIG. 12 orientation,seating can also be fully or partially accomplished by movingquasi-spherical heads 148 in an upward direction relative to the bores.In this regard, depending on the sizes and shapes of the variouscomponents, it is possible to make the connections with no portions ofthe shafts ever entering the bores. Although not necessary to broaderaspects of the disclosure, the walls of the bores extend fully aroundthe seated heads, e.g., with no breaks or openings in the walls thatform the frustoconcial bore shapes. In some forms, a screw will beadvanced to a desired final location in a bone before a quasi-sphericalscrew head is locked in a female bore of a device, for example, where aplate is impacted down onto a pre-positioned screw so that thequasi-spherical member is forcefully received and locked in the femalebore.

Turning now to FIG. 13A, shown is a top view of an orthopedic plate 200according to one embodiment of the present disclosure. From this view,plate 200 is shown to include a generally rectangular bore or opening201. Although not necessary to broader aspects of the disclosure, therectangular opening extends entirely through the plate, i.e., in adirection into the page based on the FIG. 13A illustration. Such anopening can be an elongated or slot-type opening of any suitable sizeand rectangular or non-rectangular shape. A plate or other device canincorporate any number of such openings. Illustratively, such an openingcan have one dimension (e.g., rectangular slot length when viewed fromthe top as in FIG. 13A) that is significantly larger than anotherdimension (e.g., rectangular slot width) including but not limited to afirst dimension that is 2 to 40, or 4 to 20, or 8 to 15 times largerthan a second dimension. An elongated or slot-type opening can havecurvature along its length, for example, even providing in someembodiments an annular or ring-shaped slot with no ends. Also, althoughthe width of the opening 200 in FIG. 13A is constant along its length,it need not be. Such a slot can be a series of discernable openings orbores like those shown in FIGS. 11 and 12 which are interconnectedacross a plate or other device, for example, interconnected by slots orpassages of a smaller width or dimension that allow interbore movementof another assembly component such as horizontal movement of a screw orfastener shaft from one bore to another along a plate or other devicebefore the screw or fastener is ultimately locked in place in aparticular bore. Any such elongated or slot-type opening can be part ofany plate or non-plate orthopedic device in accordance with the presentdisclosure.

FIG. 13B shows a cross-sectional view taken along view line 13B-13B fromFIG. 13A, and it can be seen that walls 202 of the opening are angled ortapered. Based on the FIG. 13B orientation, the walls diverge movingfrom top to bottom so that the top end of the opening 201 is smallerthan the bottom end of the opening. Based on the FIG. 13B illustration,a connection with a quasi-spherical member or other male-type connectorin accordance with the present disclosure can be achieved by movingplate 200 in a downward direction onto the quasi-spherical member (e.g.,which forms all or part of a screw head) so that the quasi-sphericalmember enters the opening through the larger bottom end of the openingand moves a distance in the opening toward the smaller top end untilsuitably locked in place. Alternatively, the plate could be flipped overfrom what is shown in FIG. 13B, and a leading tip of a screw could bepassed into and through the opening, and the screw could be advanceduntil a quasi-spherical head of the screw is locked into the opening.

That such openings can have an elongated or slot-type shape allows aquasi-spherical member such as that of the screw shown in FIG. 10, priorto being locked in place, to be moved to different relative positionsalong the length of a slot or other opening. For example, when viewingthe FIG. 13A illustration, such a quasi-spherical member could bereceived and locked in place in the opening at or near one end of theopening, at or near the far opposite end of the opening, or anywhere inbetween. Although not necessary to broader aspects of the disclosure, atopposite ends of the rectangular opening, the opening 201 is tapered onthree sides. Alternatively, the illustration of FIG. 13B can representone end of plate 200 such that it is not a cross-sectional view of plate200 but rather an end view. In this regard, a quasi-spherical membercould be partially and loosely received in the opening, and the platecould be slid over a quasi-spherical member (e.g., from the side) beforea connection is made. Such a configuration could be particularly useful,for example, where space is limited anatomically such as where it is noteasy or possible to introduce a plate or device other than from theside. Such side openings could be located anywhere on a plate or otherdevice.

FIG. 13C shows part of an orthopedic plate 210 according to anotherembodiment of the present disclosure. Plate 210 includes a top surface211 and bottom surface 212. This plate is similar to that shown in FIG.13B except that it includes an opening 213 which extends only partiallythrough the plate, and in this regard FIG. 13C represents across-sectional view of the plate taken from a similar vantage point asthe cross-sectional view in FIG. 13B. In particular, opening 213 extendsinto the plate from bottom surface 212, and walls 214 of the openingconverge moving toward the top surface 211 of the plate. Alternatively,the illustration of FIG. 13C can represent one or both ends of plate 210such that it is not a cross-sectional view of plate 210 but rather anend view. In this regard, a quasi-spherical member could be partiallyand loosely received in the opening, and the plate could be slid over aquasi-spherical member (e.g., from the side) before a connection ismade. Such a configuration could be particularly useful, for example,where space is limited anatomically such as where it is not easy orpossible to introduce a plate or device other than from the side. Suchside openings could be located anywhere on a plate or other device.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A ball-side prosthesis for articulating with asocket in a ball and socket joint in a patient, comprising: anarticulating ball member that includes a top side and a bottom side, thetop side providing a convex articulating surface for articulating withsurfaces in the socket, the bottom side including an opening into atapered bore that extends into the articulating ball member from saidbottom side toward said top side, said tapered bore including a smoothinner wall; a fixation member anchorable to a bone of the patientremaining on the ball side of the ball and socket joint; and aquasi-spherical member disposed at a proximal end of the fixationmember, the quasi-spherical member positionable in the tapered bore ofthe articulating ball member and including a textured outer surface forcontacting the smooth inner wall of the tapered bore when thequasi-spherical member is positioned in the tapered bore of thearticulating ball member for immovably fixing the orientation of thequasi-spherical member relative to the articulating ball member as aresult of forcible contact between one or more portions of the texturedouter surface and the smooth inner wall, the textured outer surfaceincluding at least one of a plurality of generally planar faces, aplurality of surface elements with polygonal perimeters, or athree-dimensional tessellation incorporating polygonal surfaces.
 2. Theball-side prosthesis of claim 1, wherein the textured outer surfacecovers from about 50% to about 80% of the quasi-spherical member.
 3. Theball-side prosthesis of claim 1, wherein the textured outer surfaceincludes a plurality of generally planar faces.
 4. The ball-sideprosthesis of claim 3, wherein the plurality of generally planar facesare contiguous with one another on the quasi-spherical member.
 5. Theball-side prosthesis of claim 3, wherein the plurality of generallyplanar faces have a combined area that covers 25% or more of thequasi-spherical member.
 6. The ball-side prosthesis of claim 5, whereinthe plurality of generally planar faces have polygonal perimeters. 7.The ball-side prosthesis of claim 3, wherein the plurality of generallyplanar faces have rectilinear perimeters.
 8. The ball-side prosthesis ofclaim 7, wherein the plurality of generally planar faces have polygonalperimeters.
 9. The ball-side prosthesis of claim 8, wherein theplurality of generally planar faces have triangular perimeters.
 10. Theball-side prosthesis of claim 1, wherein the textured outer surfaceincludes a plurality of surface elements with polygonal perimeters. 11.The ball-side prosthesis of claim 10, wherein the plurality of surfaceelements are planar within the polygonal perimeters.
 12. The ball-sideprosthesis of claim 10, wherein the plurality of surface elements arecontiguous with one another on the textured outer surface.
 13. Theball-side prosthesis of claim 11, wherein the polygonal perimeters arecontiguous with one another on the textured outer surface.
 14. Theball-side prosthesis of claim 1, wherein the textured outer surfaceincludes a three-dimensional tessellation incorporating polygonalsurfaces.
 15. The ball-side prosthesis of claim 1, wherein thequasi-spherical member approximates a honeycomb of polyhedral cells. 16.The ball-side prosthesis of claim 1, wherein the planar surfaces have acombined area that covers 25% to about 50% of the quasi-sphericalmember.
 17. A humeral prosthesis for articulating with a glenoid cavityin a patient, comprising: a humeral head member that includes a top sideand a bottom side, the top side providing a convex articulating surfacefor articulating with surfaces in the glenoid cavity, the bottom sideincluding an opening into a conically tapered bore that extends into thehumeral head member from said bottom side toward said top side; afixation member anchorable to a humerus of the patient; and aquasi-spherical member disposed at a proximal end of the fixationmember, the quasi-spherical member positionable in the tapered bore ofthe humeral head member and including a textured outer surface forcontacting smooth inner walls of the tapered bore when thequasi-spherical member is positioned in the tapered bore of the humeralhead member for immovably fixing the orientation of the quasi-sphericalmember relative to the humeral head member as a result of forciblecontact between one or more portions of the textured outer surface andthe smooth inner wall, the textured outer surface including a pluralityof outermost extensions that are spaced from one another on the texturedouter surface and which define a first radius of the quasi-sphericalmember and a plurality of innermost depressions that are spaced from oneanother on the textured outer surface and which define a second radiusof the quasi-spherical member, wherein the plurality of innermostdepressions occur on planar surfaces on the quasi-spherical member. 18.The humeral prosthesis of claim 17, wherein the textured outer surfaceincludes a three-dimensional tessellation of triangular surfaces whosevertices provide the plurality of outermost extensions.
 19. The humeralprosthesis of claim 17, wherein the bore includes a tapered bore segmentfor contacting the textured outer surface of the quasi-spherical memberwhen the quasi-spherical member is positioned in the bore of the humeralhead member for immovably fixing the orientation of the quasi-sphericalmember relative to the humeral head member, the tapered bore segmentincluding a first diameter that is twice the first radius and a seconddiameter that is twice the second radius, the second diameter beingsmaller than the first diameter and being positioned farther away fromthe opening than the first diameter.
 20. The humeral prosthesis of claim17, wherein the plurality of outermost extensions are deformable uponforcible contact with the walls of the bore for fixing the position ofthe quasi-spherical member relative to the position of the humeral headmember.